The research is aimed at characterizing the responses of various media to optically triggered events. The triggering involves electronic excitation, electron transfer, photochemical reaction and ligand release. The various media include model solvents and proteins. The specific goal is to learn how proteins respond to changes in the structure or charge distribution of chromophores imbedded in them or to charge separation. The novel method of transient infrared spectroscopy will be used in order that the vibrational frequencies and dynamics of the equilibrium distribution can be evaluated. Specifically, experiments will be carried out on electron transfer processes in reaction centers from photosynthetic bacteria and model systems in which the incoherent and coherent responses will be explored. Ligand release experiments on hemoglobin and myoglobin are planned to investigate the resulting protein conformational change. Also the structural responses of the 'de novo' synthesized proteins will be studied by infrared methods. Efforts are underway to devise new methods of understanding the IR spectra of proteins using hole burning.